package cn.hl.delay;

import org.apache.rocketmq.client.consumer.DefaultMQPushConsumer;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyContext;
import org.apache.rocketmq.client.consumer.listener.ConsumeConcurrentlyStatus;
import org.apache.rocketmq.client.consumer.listener.MessageListenerConcurrently;
import org.apache.rocketmq.common.message.MessageExt;

import java.nio.charset.StandardCharsets;
import java.util.List;

public class Consumer {

    public static void main(String[] args) throws Exception{
        // 1.实例化消费者
        DefaultMQPushConsumer consumer = new DefaultMQPushConsumer("consumer_delay_group");
        // 2.设置NameServer的地址
        consumer.setNamesrvAddr("localhost:9876");
        // 3.订阅一个或者多个Topic，以及Tag来过滤需要消费的消息
        consumer.subscribe("topic_delay", "tag_delay");
        // 4.注册回调实现类来处理从broker拉取回来的消息
        consumer.registerMessageListener(new MessageListenerConcurrently() {
            @Override
            public ConsumeConcurrentlyStatus consumeMessage(List<MessageExt> msgs, ConsumeConcurrentlyContext context) {
                try {
                for (MessageExt msg : msgs) {
                    System.out.println(new String(msg.getBody(), StandardCharsets.UTF_8));
                }
                // 标记该消息已经被成功消费
                return ConsumeConcurrentlyStatus.CONSUME_SUCCESS;
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return ConsumeConcurrentlyStatus.RECONSUME_LATER;
            }
        });
        // 启动消费者实例
        consumer.start();
        System.out.printf("Consumer Started.%n");
    }
}
